Title: Chunky Monkey

A/N: First Teen Wolf fic EVER. Prompts were 'sexy fight', 'doppelganger', 'ice cream', 'construction site' and 'wizards'.

Okay, so it all starts with Stiles finding a picture of Derek from high school.

XXX

Mister-permanently-sour-wolf is out somewhere – brooding or chasing squirrels, who cares – and Stiles is waiting with Scott back at the ruined childhood home for Derek to come back from his journey of self-discovery. Or rage. Either or.

Stiles goes upstairs while Scott stays downstairs, watching the door and listening for Derek's arrival like a good little wolf-boy. There have to be some perks to his best friend becoming a werewolf.

Stiles ends up in a bedroom that almost looks liveable, if you ignore the mold and burn marks, and assumes it must be Derek's. Everything is neat, ancient-looking and mysterious. And it makes Stiles fingers twitch with how much he wants to snoop around and find incriminating or embarrassing items.

Maybe Derek has a dildo collection; it could happen.

So there's a photo album tucked under Derek's pillow – which Stiles found when he threw himself gracelessly onto the bed, only to have his skull ache from making painful contact with said deadly object – and Stiles slides it out carefully. It's a solo photo album – which makes it even better because Stiles won't have to feel bad about laughing at dead werewolves in weird, dorky shots.

Be honest now; everyone has at least one bad photo – supernatural creature or not.

Derek as a baby – cute.

Derek as a kid – still cute, and smiling. (Stiles would think about how gorgeous the smile is, if it didn't make him feel like a pedophile.)

Derek as a pre-teen – grumpier, but still cute somehow.

Derek as a teen – Harry Potter?

Seriously he even has a weird scar across his forehead (probably hadn't healed yet), round glasses and bangs. Bangs that aren't perfectly flipped into an upward thing that makes you just want to mess it up to see how good his hair gel is.

Stiles spends the next ten minutes crying laughing because of all the teenage Derek photos in the album. How he's always fighting to keep his face serious and grumpy, his glasses often falling off, and his hair not doing much more than hiding his jagged eyebrows. They're good eyebrows, don't get him wrong, they just don't work with the narrower, younger Derek face.

XXX

Derek is waiting in the parking lot for Stiles and Scott to appear. It's been fifteen minutes since the bell rang, and they still haven't come out. He assumes they must have done something stupid again, and ended up in detention.

Why can't they just blend in, and relax like he does?

Some kid rushes out through the doors, and across the parking lot in record speed. He couldn't make out the face but…Derek sniffs the air, and yeah, that's Stiles's smell. He might as well follow Stiles if he wants to find Scott.

XXX

When Stiles gets bored of seeing how perfect Derek's face has been since birth, he shuffles down the stairs and back at Scott's side. Scott is scooping out spoon after spoon of ice cream, and Stiles is insulted.

"Dude, you got ice cream and you couldn't tell me about it?" Stiles says, feeling petty, but ultimately not giving a shit.

Scott, the asswipe, licks his fingers. "I totally did. But you were so busy being a spy that you didn't hear me."

For a moment, Stiles thinks he has some 'wolfy' powers because he can practically feel the lie permeating from Scott's body. "You traitor! Give me some!" He reaches out the yank the pot away, but Scott's nails come out and grip the sides tightly. "Hey, man! Didn't your mom ever teach you manners?"

Scott growls, all dog-like and non-threatening at all because Stiles has heard him make the same noises during gym class, back when he still needed an inhaler.

"Get your own, Stiles," Scott answers childishly, moving across the living room with a spoonful of ice cream in his mouth. "Chunky Monkey is my favourite, and you know that."

Stiles gapes. "Are you having like werewolf PMS or something? What's up with you?"

Scott's eyes shift to the side, and he lies. Poorly. Again. "Nothing! I'm just hungry," he snaps.

Stiles rushes in to tackle Scott, and Scott's grip on the container falters. He tries to catch it before it hits the ground, but so does Stiles and they end up ripping it apart (probably more Scott's fault – you know claws and all) and it splatters to the ground, painting them both in yellow and white melted dessert.

Scott lunges at Stiles, and Stiles lunges right back. It is so on now, baby.

XXX

Stiles is running through a construction site, and Derek's Camaro won't fit between the cones or underneath the yellow tape, so he puts it in park.

When he steps out, something tells him that he's made a mistake somewhere along the way. The scent though, he knows he isn't wrong. And that kid, even though he's getting further away, Derek can see the short hair, the hoodie, the dark running shoes and the loose jeans.

That is typical Stiles, right?

Stiles continues running across the construction site. He dips below beams, jumps over holes, circles around equipment, but doesn't once notice he's being followed. All his movements are smooth, fluid, and confident.

Meaning, it's nothing like usual Stiles. Something feels off.

Derek stops chasing for a moment to make sure that his senses haven't been playing tricks on him. He closes his eyes and breathes in the air, inhaling as Stiles would his beloved curly fries. It's definitely Stiles's smell, he confirms.

With renewed vigour, Derek takes off after the teen, half-shifting to save time and catch up sooner rather than later. When he's finally right behind Stiles, the boy turns around and – Derek is flabbergasted.

Who the fuck is this guy?

The teen, who is definitely not Stiles but smells unmistakably like him for some reason, takes out his earphone and says, "Uh. Do I know you?"

Okay, so maybe Derek said it aloud due to the frantic realization that his senses can't be trusted anymore. But – Derek heaves in a large gulp of air - why does this kid have Stiles's smell?

The teen makes a face as though Derek is wasting his time – his time, imagine that – and Derek's infamous fury surfaces. All he sees is red. Red like the blood he draws accidentally when he reels back and knocks the kid right down onto his ass.

There's a moment of panic (but no guilt really), and Derek kneels down to check the teenager's pulse.

He's still alive, thankfully, but unconscious nonetheless. And, because Derek has anger issues he refuses to deal with, he's now stuck waiting for this stranger to get back up so he can ask where the real Stiles is. (Then he can hunt down Stiles like a prey, and take out all his current frustration on his favourite chew-toy.)

Derek sits down next to the teen, and concentrates on taking in the scent surrounding him. Now that he's closer, clearer-minded, it's obvious he doesn't smell like Stiles, but that he's wearing something that belongs to Stiles. Otherwise, Derek's wolf wouldn't have been confused to begin with.

He pushes the teen's arm gently to wake him, and he doesn't even flinch. Derek sighs.

And just waits.

XXX

Ten or fifteen minutes later, when Derek is almost falling asleep, the kid stirs. As soon as his eyes land on Derek, he squeaks, and Derek rolls his eyes in response. The teen prepares to run away, despite his recent knockout (concussion?), and Derek grabs his arm before he even gets a foot under him.

"You're wearing something of Stiles's, aren't you?" Derek's priority list had changed at some point when his wolf's pride was hurt. Scent mystery solving first, locating of the irritating pack members later.

"It-it's just his sweater," the teen stutters out. "Mine fell in the toilet during lunch, and he said I could borrow his." He flinches when Derek growls low, irritated. "I don't need it anymore! I can give it back to you!"

"Good." Derek stands, putting his hand out, and waiting for the teen to strip away the scent that shouldn't be anywhere near his. The teen forces a polite smile as he gives it to Derek. "Where is Stiles? Why didn't he leave at the same time as you?"

Once again: who is this fucking guy anyway?

"My name is Tom," he ducks when Derek looks like he's going to swing again. "I'm on…the lacrosse team with Stiles." Derek gestures for Tom to get on with it and answer the question he really wants the answer to. "A-and Stiles left with Scott. They skipped their last class."

Tom covers his face with both hands when Derek snarls. But it's not aimed at Tom; it's aimed at those two idiots who never warn Derek about their plans and always make him waste his time. Like right now.

"Thanks," Derek mutters as he turns and leaves. He has a feeling he knows exactly where they went.

XXX

Somehow, Stiles is the one who has Scott in a headlock, but his victory doesn't last for long. Scott breaks away from the hold easily and stands up, growling at Stiles. When that fails to scare Stiles, Scott rips his shirt right down the middle, and shows off his massive, sharp teeth.

Stiles is not having any of that werewolf bullshit.

He tries to rip his shirt, too, and ends up bending his pinky finger in some odd way – which makes him yelp instead of growl like he'd meant to. Real scary stuff. But, hey, at least it doesn't stop him from tackling Scott when Scott stops being an asshole to ask if Stiles is okay.

They end up scratching each other, rolling around across the floor with their legs intertwined, and collecting dust with the sticky melted ice cream that's coating their bodies.

It's like mud-wrestling, but with melted ice cream instead. And a bit more sticky.

Stiles fake-whimpers and Scott – the sucker that he is – eases up. And that's when Stiles uses his pathetically human teeth to cause some temporary damage on Scott's bicep. Revenge has never been as sweet as Chunky Monkey on your best friend's skin.

XXX

Derek returns to find them still tangled up and shirtless, much sweatier now though, and his blood begins to boil. It's one thing to skip classes, and finally show Derek that they want to be in his pack, but it's another to skip classes in favour of humid, teenaged wrestling in Derek's living room.

"What are you doing?" Derek rumbles, slamming the front door behind him.

Scott answers, a bit winded, "We skipped class to get here earlier."

Derek's nails dig into his palms as he clenches his fists. "You always say how pack business is not your priority. You made that very clear."

Stiles raises a brow, twisting Scott's nipple when Scott tries to sink his fangs in Stiles's shoulder. "You always complain we don't take it seriously, dude. And now we are, and you seem mad, so what the hell?"

Derek's eyes flash red at the disobedience of his so-called pack. But it's short lived. He completely forgets what they were even discussing when it dawns on him that they're half naked (Scott helped Stiles rip his shirt off, the bastard), and sticky with some questionable, white substance.

If he didn't know better, he'd think he just walked in on the teenagers post-coital. That is not something he wants to see or know about, and he definitely doesn't want them doing it in his family home.

"Get up," Derek grinds out menacingly.

Stiles is feeling more rebellious than usual, so Scott's attempt at standing is cut short by Stiles when Stiles stretches out a leg and trips him.

Derek's growl has never been louder or more frightening. Ever.

He grabs them both by their – well, if they weren't shirtless, it would be their collars – neck, and loosens his grip on Scott when they're finally standing. Meanwhile, his grip on Stiles's arm is almost bruising. Scratch that, definitely leaving a bruise.

"Go get some air. Now," Derek orders, seething.

For a moment, Stiles wonders how he can do that if he's being gripped so hard his circulation is flowing backwards. And then Scott is out of the house, and running into the woods. Stiles is alone with an angry alpha, and thoroughly afraid for his life.

Derek lets go of Stiles's arm and walks over to the front door where Stiles's sweater was dropped. He throws it at Stiles head so roughly it actually almost becomes an efficient weapon. Anything Derek uses on Stiles could turn into an item made to kill.

Stiles mumbles, "Thanks."

Derek crinkles his nose in disgust and stalks up his stairs, slipping into his bedroom. In his bedroom where Stiles left the photo album open – right on the Harry Potter picture.

Derek snaps the album shut, and tucks it back under his pillow. Taking three, calming breaths before he (still) ends up shouting. "Stiles!"

Tugging his sweater the rest of the way down, Stiles gulps.

Stiles considers escaping, but what are the odds of him getting to the safety of his Jeep? Derek is a super-powered being, and Stiles is just an awkward teenager. Derek would catch him without even breaking a sweat.

The silence that Stiles refuses to fill with a reply only makes it more obvious how furious Derek is (the thunder-like sounds he's producing would make a grown man sob), so he tries his luck at fleeing.

Stiles only has one foot out the door, and Derek is already yanking him back by the hood of his shirt.

"Ow, ow. Okay. Sorry. I was just trying to relax a bit, and that's the only comfortable place. It's your fault for leaving an album so out in the open," Stiles says, wincing as soon as the words leave his mouth.

Derek spins Stiles around and pins him to the door. "It wasn't out in the open. It was in my bed, in my bedroom, under my pillow. What else did you find?"

Stiles licks his lips, trying to shift away from the pearly white fangs. "Nothing. Even though I hoped to find a dildo collection –"

Derek glares, baring his teeth.

"Nothing, I swear. Just that. And that was an accident. God, you're seriously grumpy considering we skipped class to come over here."

Derek slams Stiles against the door. "You weren't supposed to."

Stiles swallows, fingernails scrambling to grip the wood at his back. "You always tell us—"

"Don't do it again," Derek cuts in. For some reason, this is making him angrier than a lot of other things Stiles has said and done.

Stiles frowns. "Okay, fine. Be all bipolar on top of sour. It'll only ensure no-one ever considers trying to befriend you."

Derek narrows his eyes. "I don't need friends."

Stiles tilts his head. Because, come on, Derek makes them visit him almost daily now.

Derek can practically smell the disbelief. "I don't. Need. Friends."

Stiles wraps his fingers around the hand digging increasingly sharp nails into his collarbone. "Doesn't mean you don't want friends."

Derek snaps because that's more than enough lip from someone who should be respecting his alpha.

Derek tackles Stiles to the floor, and ruffles him up when he tries to twist away. Derek's fingers dip in the white mess on Stiles's neck, and he's afraid to smell it. He's worried the scent will be Scott'; that it will confirm his fears. And then Derek realizes it's just ice cream.

His Chunky Monkey ice cream from his freezer. That they took, and rolled in. All over his floor. Which is now sticky under his boots.

Fantastic.

"You're going to clean my living room," Derek states dryly, pinning Stiles easily to the floor when he wiggles.

"That could take a year – what with all the burnt walls and furniture, the hole in the floor, the creaky stairs—"

Derek squeezes Stiles's shoulder in warning. "I meant the mess you made just now with Scott."

"Then why isn't he helping me? He got sent away in the woods, and I'm here being scolded. This is totally unfair. And don't think I can't see a bias when there is one—"

Derek's lip twitches, amusement close behind. "Shut up." Stiles rolls his eyes, but follows the order without further protest.

Shifting to let Stiles up, Derek presses against Stiles's injured finger accidentally. Stiles whimpers, and Derek chest fills with a need to soothe; arousal suddenly taking him over. He's never heard Stiles sounding so…delicious.

What is he thinking? This is Stiles.

"I hurt my finger, dude, don't lean on it," Stiles whines, his head turned away to hide the flush high on his cheeks.

Stiles might be a good liar, but Derek can hear the racing of Stiles's heart.

Derek pushes against the hand with his hip, and Stiles winces, biting his bottom lip. Derek is mesmerized by the reaction, desperate to have those teeth against his skin, and his own teeth sinking in to that plump bottom lip in turn. He should have known there was a reason he'd been tolerating this hyperactive kid for so long.

"That was my ice cream," Derek reprimands, taking Stiles's injured hand and bringing it up to his lips. The smell on them – sugar, sweat, slow-building arousal – has Derek's eyes flickering to red without his knowledge.

Stiles sucks in a breath when he sees Derek's eyes colour going back and forth from hazel to red. "I- I didn't take it. Scott was eating it, and not sharing, and I was trying to get some when –"

"Stop." Derek presses Stiles's fingers to his nose, taking in the eager scent. His tongue traces the digits slowly, carefully tasting, searching each of them. When he finds the reason for Stiles's discomfort, Derek slips the small finger between his lips, swirling his tongue around it.

Stiles shivers, his hips rolling up and into Derek's (against his better judgment), and letting out a shaky breath when Derek scrapes his teeth across it. It's almost like Derek's trying to seduce Stiles.

"Dude, w-what a-are you doing?" Stiles's chest feels tight, and only gets tighter when Derek grins, pressing his weight down into Stiles's sinewy movements.

"What does it look like?" He leans in closer, breathing warm against Stiles's parted lips. "I'm making sure I have the right Stiles this time."

"The right me? This time?" Stiles croaks out.

Derek's tongue darts out, touching Stiles's bottom lip tentatively. He waits to see if Stiles's emotions will sway, if his arousal will dim or disappear. But it doesn't. It becomes suffocating, unbearable, and undeniable for Derek to refuse, so he takes what he's given.

The first kiss is so surprising Stiles is hiccupping when Derek pulls away.

"We can't do whatever you're planning to do. What are you planning to do? And when did this start? I mean, you know, you hate me. Don't you? And-and Scott isn't that far. You only sent him in the woods. Not that I'm saying no. I'm definitely not saying no. Who could say no? You're hot and built and –"

Derek steals another kiss, pushing past Stiles's lips until his tongue is curling against skin and teeth. A vibration is travelling through him, reverberating between their bodies, and Stiles is suddenly everywhere at once. He's sucking at Derek's lips and kissing back, hands all over Derek, pulling at clothes and flesh, biting, gnawing, and making all these noises.

The day's getting better at last.

Stiles breaks the kiss for a moment, hands snaking in the back of Derek's pants, squeezing his ass. Derek thought that his mind had shut off, but apparently not quite.

"Scott. Scott will find us. Unless we're just making out, which I'm totally okay with. Your mouth is like a holy blessing of the supernatural variety –"

Derek snorts, a finger pressing to Stiles's lips. "I intend to take a lot more than your first kiss." Stiles whimpers, scraping his nails across the flesh of Derek's ass. "And since Scott took my ice cream, I'm going to have to cover you in something else that looks about the same."

Stiles's eyes widen, the scent of his excitement looming over Derek like a thundercloud.

"Every single part of you," Derek continues, grinning devilishly. He cups Stiles's cheek, and laughs when Stiles makes a sound like he's dying. "Speechless?"

Stiles shakes his head slowly. "I'm just wondering; can you come that many times?"

Derek tries not to smile (but fails of course), and smothers Stiles with another kiss when Stiles tries to look smug about it.

We'll see just who will have the last laugh, Stiles.